#!/usr/bin/env python
# -*- coding:utf-8 -*-

def exam01():
    data = 'Hello World'
    a = int(input())
    if a == 0:
        res = data
    elif a > 0:
        res = []
        for i in range(0,len(data),2):
            res.append(data[i:i+2])
        res = '\n'.join(res)
    else:
        res = '\n'.join(data)
    print(res)

a = input()
res = '%.2f' % eval(a)
print(res)
